1. Field of the Invention
The present invention relates to a registration pin for a rotating drum used in a recorder device. The recording device may be an external drum recorder. The registration pin cooperates with a film to register and support the film during loading of the film onto the drum. The registration pin has a reduced profile to reduce the overall diameter of the drum. The pin also has a construction that accommodates loading of different types of films onto the drum.
2. Description of Related Art
Conventional registration pins support the film or sheet material on a rotating drum mainly through the, height of the pin above the surface of the drum. The pins, however, lack structure to retain and hold the film on the drum during rotation. In the conventional pins, holding and retention is achieved by placing at least one hole in a film and placing the at least one hole over a corresponding pin on a rotatable drum. Further, the operator of the device usually places some additional means to support and position the film at an edge of the film. This additional means may take the form of an adhesive tape or the like. Furthermore, the drum may also have structure, usually a vacuum, to hold the film against the drum during rotation.
Conventional registration pins have a head that extends a substantial height above the surface of the drum. In some applications, a charger or other ancillary device is required to be located close to the film and drum surface to permit the device to function satisfactorily. The height of the head in conventional registration pins is the main component of the pin that serves to hold the film in place. That is the film abuts against the head of the pin and if the film is subjected to any vertical movement, the film stays on the pin as long as the film can abut the head of the pin.
The pin having a substantial height may, however, interfere with an ancillary device. With a registration pin having a substantial height, the overall distance of the drum to the device must be increased, which is inconvenient and undesirable to achieve proper and clear images and to achieve a compact design of the overall apparatus.
With a pin having an enlarged head, a large gap from the drum surface to a charger is needed. This large gap is particularly ineffective with certain types of film chargers, especially using a digital film charger, such as a migration imaging film charger. In migration imaging film usage, the film is made sensitive to light by an electric charge. The film is developed through heat and does not require chemicals or water. This is advantageous as the migration imaging film is capable of safe and casual disposal.
The height of the conventional pin requires the external drum recorder in a migration imaging film charger to be placed a substantial distance from the drum's surface in order to clear the registration pins. Consequently, the migration imaging film chargers are ineffective when using conventional pins with enlarged heads, due to the required clearance distance.
FIGS. 1A and 1B show one type of conventional registration pin. Registration pin 1 is generally cylindrical and has body or shaft 1' and an enlarged head 2. The pin is introduced into the a hole in the drum in a well-known manner, including press-fit, adhesive or a threaded shaft.
The enlarged head 2 has an overall height dimension d in the order of about 0.120 inches. This overall head height dimension d does not permit an effective placement of a film charger near the drum surface.
FIGS. 2A and 2B show another form of a conventional registration pin 1A. Pin 1A includes an enlarged head 2A. The head 2A has flattened sections 3A, where a cord has been removed from the head. The cords have been removed from diametrically opposite sides of the head. While these flattened sections may assist in supporting and registering placement of the film onto the drum, pin 1A still has the disadvantageous enlarged head. The enlarged head 1A has an overall height d, about 0.120 inches from the surface of the drum.
The film has holes punched in an edge of the film. An operator places the film over the pins of the drum. Whereas, the height of the pins alone support and position the film on the drum, the operator usually places a tape or the like on the film edge with the holes to additionally support and position the film on the drum.
As can be seen from FIGS. 1A and 2A, the pins are mounted on a drum 5' of a recorder device. The heads 2 and 2A extend a distance d above the surface of the drum 5'. The overall height of each head 2 and 2A requires a film charger, especially a migration imaging film charger, to be placed a large distance from the drum surface 5'. This placement results in an ineffective operation of the recorder and lends to unsatisfactory recording results.